package org.example.gateway.handler;

import com.alibaba.fastjson.JSON;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.web.reactive.error.ErrorWebExceptionHandler;
import org.springframework.cloud.gateway.support.NotFoundException;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.annotation.Order;
import org.springframework.core.io.buffer.DataBufferFactory;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.security.oauth2.common.exceptions.InvalidTokenException;
import org.springframework.web.server.ResponseStatusException;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;

import java.util.HashMap;
import java.util.Map;

/**
 * 网关统一异常处理
 *
 */
@Order(-1)
@Configuration
public class GatewayExceptionHandler implements ErrorWebExceptionHandler
{
    private static final Logger log = LoggerFactory.getLogger(GatewayExceptionHandler.class);

    @Override
    public Mono<Void> handle(ServerWebExchange exchange, Throwable ex)
    {
        if (exchange.getResponse().isCommitted())
        {
            return Mono.error(ex);
        }
        String msg;
        if (ex instanceof NotFoundException)
        {
            return invalidErrorMono(exchange,404, "服务未找到");
        }
        else if (ex instanceof ResponseStatusException)
        {
            ResponseStatusException responseStatusException = (ResponseStatusException) ex;
            return invalidErrorMono(exchange,500,responseStatusException.getMessage());
        }
        else if (ex instanceof InvalidTokenException)
        {
            InvalidTokenException responseStatusException = (InvalidTokenException) ex;
            msg = responseStatusException.getMessage();
            return invalidErrorMono(exchange,responseStatusException.getHttpErrorCode(),msg);
        }
        else
        {
            msg = "内部服务器错误";
        }
        log.error("[网关异常处理]请求路径:{},异常信息:{}", exchange.getRequest().getPath(), ex.getMessage());
        return invalidErrorMono(exchange,500,msg);
    }



    private Mono<Void> invalidErrorMono(ServerWebExchange exchange,Integer code,String msg)
    {
        ServerHttpResponse response = exchange.getResponse();
        response.getHeaders().setContentType(MediaType.APPLICATION_JSON);
        response.setStatusCode(HttpStatus.OK);
        log.error("[网关异常处理]请求路径:{}", exchange.getRequest().getPath());
        return response.writeWith(Mono.fromSupplier(() -> {
            Map result=new HashMap();
            result.put("code",code);
            result.put("msg",msg);
            DataBufferFactory bufferFactory = response.bufferFactory();
            return bufferFactory.wrap(JSON.toJSONBytes(result));
        }));
    }



}